https://doi.org/10.1140/epjc/s10052-018-5960-4
Regular Article - Theoretical Physics
Octet baryon magnetic moments at next-to-next-to-leading order in covariant chiral perturbation theory
1
School of Physics and Nuclear Energy Engineering, Beihang University, Beijing, 100191, China
2
State Key Laboratory of Nuclear Physics and Technology, School of Physics, Peking University, Beijing, 100871, China
3
Institut für Theoretische Physik II, Ruhr-Universität Bochum, 44780, Bochum, Germany
4
School of Physics and Nuclear Energy Engineering and Beijing Key Laboratory of Advanced Nuclear Materials and Physics, Beihang University, Beijing, 100191, China
5
China and Beijing Advanced Innovation Center for Big Date-based Precision Medicine, Beihang University, Beijing, 100191, China
6
Helmholtz-Institut für Strahlen- und Kernphysik and Bethe Center for Theoretical Physics, Universität Bonn, 53115, Bonn, Germany
7
Institute for Advanced Simulation, Institut für Kernphysik and Jülich Center for Hadron Physics, Forschungszentrum Jülich, 52425, Jülich, Germany
* e-mail: lisheng.geng@buaa.edu.cn
Received:
14
March
2018
Accepted:
31
May
2018
Published online:
12
June
2018
We calculate the octet baryon magnetic moments in covariant baryon chiral perturbation theory with the extended-on-mass-shell renormalization scheme up to next-to-next-to-leading order. At this order, there are nine low-energy constants, which cannot be uniquely determined by the seven experimental data alone. We propose two strategies to circumvent this problem. First, we assume that chiral perturbation theory has a certain convergence rate and use this as one additional constraint to fix the low-energy constants by fitting to the experimental data. Second, we fit to lattice QCD simulations to determine the low-energy constants. We then compare the resulting predictions of the light and strange quark mass dependence of the octet baryon magnetic moments by the three mostly studied formulations of baryon chiral perturbation theory, namely, the extended-on-mass-shell, the infrared, and the heavy baryon approaches. It is shown that once more precise lattice data become available, one will learn more about the convergence pattern of baryon chiral perturbation theory.
© The Author(s), 2018
